"Do you know that dog?"
Translation:Znacie tamtego psa?
ok now i know when i use the accusative case i have first to split between gender neuter,male and gender female
if female i have alays to use accusative
if male and neuter are objects i have to use nominative case, if are persons or animals i have to use accusative case, but now i'm learning that if gender is neutral i have to use nominative case as well.... am i right ?
No no no. The cases are not dependent on the gender. The cases are dependent on their function in the sentence, on the verb that was used, on the preposition they follow... things like that. Every gender has a form for every case.
So in singular, you have: masculine (ten pies = this dog), feminine (ta książka = this book), neuter (to dziecko = this child). These are the Nominative forms, the dictionary ones.
Both "kochać" and "znać" from your comment take Accusative. Accusative is probably the most often used case. However, there is one thing that gets more complicated here: the masculine gender.
In Accusative, masculine divides into animate and inanimate. On top of that, a big number of nouns (mostly food and beverages) are considered grammatically animate despite any logic. So for masculine you have two versions of "this": "ten" (for inanimate nouns) and "tego" (for animate nouns). So, take "widzieć" (to see):
Widzę ten stół (I see this table), but Widzę tego psa (I see this dog).
Complicated? Well, yes, definitely. But you will get around it with enough practice :)
It's neuter. Animate/inanimate doesn't matter. With gender-neuter nouns, accusative = nominative. In this example, to dziecko is still in the accusative case, it's just that it's identical to nominative. It took me some time to get used to these differences of gender and case
If you had "Do you know this child?" that would be "Znacie to dziecko?" - but that's not Nominative, that's Accusative. Yes, as va-diim wrote, it looks the same, but you have to know that it is Accusative because for some other genders it's not identical to Nominative. Gender doesn't determine the case. Gender is attributed to the word, and you have to find the proper form to match the case that you need. Here, the verb "znać" needs Accusative.
There are some glitches sometimes, true, although users rarely provide screenshot that prove that this is what happened ;)
"Czy znacie tamtego psa?" definitely should have worked. Including the subject pronoun is usually totally unnecessary, as it is known from the form of the verb. So mostly it emphasizes the subject, shows some contrast.
Look at the basic, Nominative form of the noun. Your first assumption should be:
It ends with a consonant - it's probably masculine.
It ends with -a - it's probably feminine.
It ends with -o, -ę, -um - it's almost certainly neuter.
You have exceptions of course, even in some quite basic words (masculine mężczyzna or tata, feminine mysz), you just have to learn those.
To add to what va-diim wrote, the gender of the animal can matter. There is one 'default' word for the species, and it has its own gender (masculine "pies" for a dog, feminine "kaczka" for a duck, etc.), but if you feel the need to specify the gender of some particular animal and it's not the 'default' gender of this species, then there will be a word for it (e.g. "suka" or "suczka" for a female dog, especially the first one is quite risky as it's basically equivalent to "bitсh"; "kaczor" for a male duck - like "Donald Duck" is "Kaczor Donald" while "Daisy Duck" is "Kaczka Daisy").
Just look up any Polish word on Wiktionary.org and it will say m., f., or n.
The gender of the animal doesn't matter. It's the grammatical gender of the noun that's important, just like a fork, knife, a food item, for example, has a grammatical gender even though it has no biological gender.